Device for holding drill pipe

ABSTRACT

A device for connecting and disconnecting pipe segments of drill pipes, includes an adjustable retaining element in the form of a collar. For firmly holding the pipe segments introduced into the collar, segments acting as clamping jaws are used for retention. The clamping jaws can be adjusted vertically by servo elements for reducing the receiving diameter. The segments have a conical outside contour and a conical guide on the collar and a corresponding conical guide is provided on the collar, so that, when the segments are vertically displaced, the receiving diameter is reduced.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a device for the adjustable verticalholding of drill pipe consisting of a plurality of pipe segmentsconnected to each other in a row by connecting elements, for use ondrilling platforms, with a removable holder on the rotating table forinserting and removing drill pipe,

-   -   where a retaining element, which can be used to install or to        remove the connecting elements between the pipe segments and to        allow handling by winches is connected to the drill pipe;    -   where the retaining element is in the form of a collar, which        can be placed on the drill pipe, and which has elements in its        outer area which allow it to be connected to the winch; and    -   where the interior space of the retaining element for receiving        the drill pipe has by means of vertically adjustable segments as        clamping jaws for changing the receiving diameter with a        cylindrical receiving area.

2. Description of the Related Art

These types of arrangements are used in the area of offshore drillingplatforms to connect and to disconnect the large number of pipe segmentswhich are arranged in a row and which are connected to each other byconnecting elements. It is known that retaining elements can be turnedinto the end of the pipe segment for handling, and that a winch, locatedabove the end of the pipe, can act on these retaining elements by meansof appropriate connections so that adjacent pipe segment can beconnected to each other or disconnected from each other. The drill pipeis also held in place on the rotary table in this way to prevent it fromsliding off and from sinking in the water.

Arrangements for handling and holding drill pipe are known from DE 42 27645 A1 and DE 697 24 670 T2. In these cases, however, pipe shouldersmust be present on the drill pipe so that it can be handled. It is alsonecessary to use an intermediate ring, a so-called “setting ring”, whichpresses down the wedge-shaped elements.

These designs often cause damage and have the result that the elevatorrings used do not close properly.

SUMMARY OF THE INVENTION

The object of the invention is to create a simple retaining elementwhich ensures that the pipe segment will be held securely even in theabsence of pipe shoulders or adapter pieces with the necessary securityand that the retaining forces in the collar of the retaining elementwill be adjusted automatically by the weight of the connected pipesegments.

This object is met according to the invention in that the adjustablesegments have a conical external contour and can slide along acorresponding conical guide in the collar of the retaining element toadjust the diameter of the receiving opening, where the clamping hold onthe drill pipe being held can be adjusted by means of controllable servocylinders, which are installed above the segments and which shift thesegments vertically with respect to the collar of the retaining element,thus narrowing the receiving opening, where the servo cylinders act byway of ribs formed on the external area of the segments, and the ribs onthe segments with corresponding ribs on the collar of the retainingelement hold a guide rod for holding, which guides a compressiblecompression spring between the ribs.

As a result of this arrangement, the pipe segments can be easily handledby placing the collar onto the drill pipe to serve as a retainingelement and by adjusting the initial clamping action by way of therelatively small servo cylinders acting on the segments. The actualretaining forces are adjusted automatically by the weight of the pipesegments themselves, during which the segments shift while the retainingring serves as a bearing. Thus the servo cylinders are not required togenerate the holding forces for the pipe segments but instead servemerely to produce the initial clamping action for carrying the pipesegments.

An advantageous embodiment is created in that, to adjust the position ofa segment, each of the servo cylinders mounted on the collar of theretaining element acts by way of a sleeve on a rib of the segment.

A simple embodiment is obtained in that the adjusting elements foradjusting the segments are formed by compressed-air cylinders mounted onthe collar.

To ensure a uniform force distribution, it is proposed that the mountedcompressed-air cylinders used as adjusting elements for the segments beconnected to each other.

To improve the fit and to increase the holding power, it is proposedthat the receiving surface of the segments for the drill pipe have bymeans of inserted clamping elements with contact surfaces in the form ofa sawtooth profile.

In addition, the retaining element is designed as a collar which can beopened and locked closed.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of the disclosure. For a better understanding of the invention, itsoperating advantages, specific objects attained by its use, referenceshould be had to descriptive matter in which there are describedpreferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWING

In the drawing:

FIG. 1 is a side view of a retaining element;

FIG. 2 is a top view of the element according to FIG. 1;

FIG. 3 is a partial cross sectional view along line III-III of FIG. 2;and

FIG. 4 is an enlarged view, in isolation, of the area marked IV in FIG.3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the illustrated arrangement, a retaining element 1 for receiving adrill pipe (not shown) in the form of a pipe segment is shown in theform of an openable collar. This collar 1 is formed by two elements 2and 3, which can swing open in a hinge-like manner. The collar can thenbe placed around a pipe segment and then closed and locked. Of course,the retaining element could be designed as a closed collar 1 with acentral receiving opening 4, into which a pipe segment can be inserted.

The cross section of the receiving opening 4 can be adjusted by the useof four segments 5, where the segments 5 are designed as clamping jawsacting on the received pipe segment and are vertically adjustable. Forthis purpose, the segments 5 have a conical outside contour 6 and acorresponding guide 7 in the collar 1 serving as retaining element 1.

The segments 5 are held in the collar 1 by guide rods 8, and the guiderods 8 are held on the segments 5 by the ribs 9 and on the collar 1 bythe ribs 10.

Above the segments 5 are pneumatic servo cylinders 11, which can becontrolled by way of lines 12 and which adjust the segments 5 verticallydownward by way of an intermediate sleeve 13. As a result of thecooperation between the conical surfaces 6 and 7, the servo cylindersreduce the size of the receiving opening 4 and thus exert a clampingaction on the received pipe segment.

The servo cylinders 11 with the interposed sleeves 13 act on the ribs 9of the segments 5.

To increase the restoring force when the clamping action is released,compressible compression springs 14 are installed on the guide rods 8between the ribs 9 of the segments 5 and the ribs 10 of the collar 1.

The servo cylinders 11 are held in place on the collar 1 by a housing15.

In this embodiment, the cylindrical receiving surface of the segments 5for the pipe segments is formed by inserted clamping elements 16 with asawtooth profile.

To insert the drill pipe and to pull it back out again, a winch isinstalled above the collar 1 holding the received pipe segment. Thewinch acts on the collar 1 from both sides by way of elements 17, whichserve as receivers for shackles 18 or the like, as indicated in FIG. 2.

As a result, the collar 1 can be fixed in place on a pipe segment tohold and adjust it, thus allowing the winch to adjust the position ofthe pipe segment as desired so that the connecting elements between thepipe segments can be installed or removed.

While specific embodiments of the invention have been described indetail to illustrate the inventive principles, it will be understoodthat the invention may be embodied otherwise without departing from suchprinciples.

1. A device for an adjustable vertical holding of drill pipe having aplurality of pipe segments connected to each other in a row byconnecting elements, for use on drilling platforms having a removableholder on a rotating table for inserting and removing drill pipe, thedevice comprising: a retaining element (1) connected to the drill pipefor installing and removing the connecting elements between the pipesegments and for handling by winches; wherein the retaining element (1)is a collar adapted to be placed on the drill pipe, and having elements(17) in an outer area thereof which allow the retaining element to beconnected to the winch; wherein an interior space (4) of the retainingelement (1) for receiving the drill pipe has a cylindrical receivingarea comprised of vertically adjustable segments (5) as clamping jawsfor changing the receiving diameter, wherein the adjustable segments (5)have a conical external contour (6) and are slidable along acorresponding conical guide (7) in the collar of the retaining element(1) to adjust the diameter of the receiving opening (4), wherein theclamping hold on the drill pipe being held can be adjusted by means ofcontrollable servo cylinders (11), which are installed above thesegments (5) and which shift the segments vertically with respect to thecollar of the retaining element (1) for narrowing the receiving opening(4); wherein the servo cylinders (11) act by way of ribs (9) on externalareas of the segments, and the ribs on the segments (5) withcorresponding ribs (10) on the collar of the retaining element (1) holda guide rod (8) for holding, which guides a compressible compressionspring (14) between the ribs (9, 10).
 2. The device according to claim1, wherein the servo cylinders (11) mounted on the collar of theretaining element (1) act by way of sleeves (13) on the ribs (9) of thesegment (5) to adjust them.
 3. The device according to claim 1, whereinthe servo cylinders (11) for adjusting the segments (5) arecompressed-air cylinders mounted on the collar (1).
 4. The deviceaccording to claim 3, wherein the compressed air cylinders (11) areconnected to each other.
 5. The device according to claim 1, whereinreceiving surfaces of the segments (5) for the drill pipe are formed byinserted clamping elements (16) with contact surfaces in the form of asawtooth profile.
 6. The device according to claim 1, wherein theretaining element (1) is a collar which can be opened and locked.